Synchronizing gears



y 1956 H. DORPMUND 2,745,529

SYNCHRONIZING GEARS Filed Sept. 23, 1954 2 Sheets-Sheet 1 May 15, 1956 H. DORPMUND 2,745,529

SYNCHRONIZING GEARS Filed Sept. 23, 1954 2 Sheets-Sheet 2 BY JQ XQ Z Uni ed States Pater r I GEARS Doi'pinund, Wolfsburg, Germany, assignor to Volkswagehwerk G. in. b. H., Woifsburg, Germany h "fine fioii sisal-rte; is, 1954, set-tn N0. 457,959

priority, application Germany September as, 1953 than. ct 192 53 ejpresent invention relates to synchronizing gears, and more particularly to synchronizing gears for a motor vehicle. t V

H ,It is an object of thepresent invention to reduce as fares possible the overall length of such a synchronizing s en.

It is another object of the present invention to reduce the weight of synchronizing gears of the kind described hereinabove I V V It is a further object of the present invention to shorten considerably the elements taking part in the switching operation of synchronizing gears of the type described hereinabove. H t V It is still another object, of the present invention to redu'cethe length of the gear shift sleeve forming part of the synchronizing gear according to the present inventiOIl-z k Other objects and advantages of the present invention will become apparent from the following detailed descripfiOl thereof when read in connectionwith the accompanying drawings showing, by way of example, an embodiment of the present invention. In the drawings:

Eig. 1 is asectional elevation of a synchronizing gear according to the present invention in neutral position; Fig, 2 is a sectional elevation of parts of Fig. l in an operative position; y it p v I Figs. 3 and 4 are, respectively, a cross-section and an elevation of a part ofFig. l; g t V Fig, 5 is a cross-section along the plane AA of Fig. ha

Fig. 6 is an elevation of a part of Fig. 1. p Referring now to the drawings, a first shaftit) is driven by the engine (not shown) and has a part 12 provided with longitudinal grooves 14. t The part' 12 of the shaft carries a sleeve 16 on which a body 18 having a toothed, rim 20 is rotatably arranged. The toothed rim 2119f the rotatable body 18 engages a toothing 22 providedpnthe outer circumference of a gear wheel 24 be ingthe third wheel of the change speed gear and being goupled by means of a coupling member 28m a second shaft 211 arranged parallel to the first shaft 10 M The second shaft 26 carries by means of a coupling memberfit) a gear wheel 32 being the fourth wheel of the change speed gear, The fourth gear wheel 32 is arranged substantially parallel to the third gear wheel 24 and has a toothing 34 engaging a toothed rim 36 formed in one piece with a toothed body 38 (termed hereinafter the ffirst body arranged loosely by means of a sleeve 4-9 on the non-fluted portion 42 of the first shaft ill. h I

A ring-shaped body 44 is rigidly connectedby coupling members 46 with the body 18 so as to rotate therewith. The ring-shaped body 44 is provided with circumferential teeth 48 adapted for alignment with the circumferential teeth 50 of an annular member 52 having a comically shaped inner portion 54 adapted to engage the sonically shaped outer portion 56 of the ring-shaped body 44. An annular disc 58 is arranged between the ring-shaped body 44 and the toothing 20 of the rotatable body 18 for a ECQ purpose to be explained more fully hereinafter in connection with the fourth gear Wheel 32.

A ring-shaped member 6% provided with circumferential teeth 62 is rigidly connected to the grooves 14 of the part 12 of the first shaft it) so as to rotate with the latter. The member 6% is provided with three equidistant circuin ferential recesses 64-, 65, and 65 (Pig. 5) which are spaced from one another by angles of substantially 120.

The circumferential recesses 64, 65, and 58 are engaged, respectively by locking members 76}, 72, 7d provided shown more fully in Fig. 1, with end portions such as 76 forming pockets for receiving spring rings '78 and iii urging the locking members 7 72, 7 outward so that the toothed parts such as 84 thereof engage the inner teeth 82 of a gear shift sleeve 86. The outer perimeter of the gear shift sleeve 86 is provided with a groove fififo'r the accommodation of the annular end 9% of a gear shift lever 92.

With the first body 3 a coupling member 4 is rigidly connected by means of second body 96 so as to rotate with the first body 1) be second body 96 has a conically shaped part ti is provided with a first circumferential teething ion adapted to engage a second toothmg 102 arranged on a ring-shaped member it'l having a conicaily shaped surface 1&6 abutting against the conically shaped part 5 8 of the second body 96 (Figs. 3 and 4). Thus it will he understood that the ring-shaped member i d acting as a synchronizing ring may be imparted a limited movement relative to the second body 96 in a direction substantially parallel to the first shaft 1! whereby the second toothing 162 of the synchronizing ring or member 1S4 is aligned with the first toothing 1% of the second body 96.

The member or synchronizing ring is provided with three circumferential recesses 1%, 11%, 112 corresponding, respectively, to the circumferential recesses 54-, 65, 6% of the member of? and forming continuations thereof. The circumferential recesses 64-68 and liiii2 are thus adapted for being engaged by the inner teeth 82 of the gear shift sleeve 85 in the operative position shown in Fig. 2.

Between the second body 96 and the toothed rim 35 of the first body 33 a stop means designed as an annular disc 114- (Pig. 6) is arranged. The annular disc 114 is firmly held between the second body 5 6 and the toothed rim 36 of the first body and has an cuter perimeter projecting beyond the first toothing 1% arranged on the second body 96 so as to limi the motion of the gear shift sleeve 86 toward the left parallel to the first shaft 10.

it should be understood that the toothings, such as 48 and 1th), of the body 44 and the part 9%, respectively, may be pressed or shrunk on the body or part 44 and 98, respectively.

The operation of this device is as follows:

When it is intended to shift the gear shift sleeve 86 from the neutral position thereof shown in Fig. 1 into the operative position thereof shown in Fig. 2 by actuating gear sl lever 92 the annular end of which engages the groove provided at he outer perimeter of the gear shift sleeve Ed, the inner teeth 32 of the latter will enter the circumferential recesses 6 i5$ of the ring-shaped member 6 3 which. receive the locking members -?4 and the spring rings 73 and However, a shifting of the gear shift sleeve into the operative position thereof shown in Fig. 2 can only be effected after the synchronizing ring 32% which abuts with the conical inner surface 166 thereof against the conically shaped part 98 of the second body 96 rotates at the same speed as the second body 96 so that the aligned first and second toothings Hill, 192 of the second body 96 and the synchronizing ring 1634 allow the inner toothing 82 or the gear shift sleeve 86 to pass so that the same reaches the operative position shown in Fig. 2.

However, a shifting of the gear shift sleeve beyond the extreme position thereof shown in Fig. 2 is prevented by the annular disc 114 held firmly between the second body 96 and the toothed rim 36 of the first body 33. The outer perimeter of the annular disc 114 projects a little beyond the first toothing 1% arranged on the second body. In consequence thereof, the motion of the gear shift sleeve 86 toward the left parallel to the first shaft is limited, the annular disc 114 acting as a stop means for the motion of the gear shift sleeve 86.

It should be understood that the present invention which has been described hereinabove in connection with the annular disc 114 associated with the fourth gear wheel 32 of a change speed gear could be equally adapted for use with the third gear wheel 24- of the change speed gear, an annular disc 53 being provided between the ring-shaped body 44 and the toothing 26 of the rotatable body 18. The annular disc 58 has preferably an outer perimeter projecting a little beyond the toothing 48 of the ring-shaped body 44.

It should be noted that according to the invention the space between a toothed part and the counterpart thereof is reduced or even obliterated. In consequence thereof, the axial length of the gear shift sleeve 86 is reduced to the minimum required for the transmitting action thereof.

Furthermore, the gear shift sleeve 86 in the operative position thereof shown in Fig. 2 is only in engagement with part of the circumferential teeth 62 of the ringshaped member 60, the right hand half of the teeth 62 being freed by the gear shift sleeve 86. Under the influence of the centrifugal force exerted on the ring-shaped member 60 and the circumferential teeth 62 thereof, the latter and the gear shift sleeve 86 have a tendency to assume an inclined position with reference to the nor-' mal position thereof which may cause a dancing movement or a pendulum movement of the gear shift sleeve 86 which thus has the tendency to come into deeper engagement with the circumferential toothings 100 and 102 which in turn leads to quick wear of the annular end 90 of the gear shift lever 92. By providing the annular disc 114 the tendency of the gear shift sleeve 86 to move in axial direction is taken up, thus relieving the load on the annular end 90 of the gear shift lever.

It should be noted that in the end position shown in Fig. 2 the right edge 116 of the gear shift sleeve 86 shortened to the least possible amount coincides approximately with the median 118 of the member 69 so that an inclined position of the gear shift sleeve 86 under the action of a centrifugal force causes a force directed to the left which is taken up by the annular disc 114. At the same time the annular disc M4 prevents a dancing or a pendulum movement of the gear shift sleeve 86.

It should be understood that many changes may be made in the form, construction, and arrangement of the several parts of the synchronizing gear described hereinabove without sacrificing any of the advantages thereof, the novel and advantageous limitations of my synchronizing gear being claimed in the claims appended to this specification.

I claim:

1. A synchronizing gear, particularly for motor vehicles, comprising, in combination, a shaft, a first body arranged loosely on said shaft, said first body having a toothed rim, a second body arranged on said first body near said toothed rim thereof, gear shifting means arranged for linear motion substantially parallel to said shaft, said gear shifting means being in toothed engagement with said second body, and an annular disc arranged at the end of said toothed rim of said first body adjacent to said second body, said annular disc forming a stop limiting the motion of said gear shifting means parallel to said shaft.

2. A synchronizing gear as claimed in claim 1, said second body being keyed to said first body, and a toothing pressed on said second body.

3. A synchronizing gear as claimed in claim 1, said second body being keyed to said first body, and a toothing being shrunk on said second body.

4. A synchronizing gear, particularly for motor vehicles, comprising, in combination, a shaft, a first body arranged loosely on said shaft, said first body having a. toothed rim, a second body arranged on said first body in fixed axial relationship thereto near said toothedr'im thereof, said second body having a conically shaped part, a disc-shaped part arranged for rotation with said shaft and extending near said conically shaped part of said second body, a first toothing arranged on said second body, a ringshaped member having a conically shaped surface abutting against said conically shaped part of said second body so that said ring-shaped member may be imparted a limited movement relative to said second body in a direction substantially parallel to said shaft, a second toothing arranged on said ring-shaped member and being arranged for alignment with said first toothing arranged on said second body, said disc-shaped part and said ringshaped member being provided with equidistant circumferential recesses, locking means arranged, respectively, in said circumferential recesses of said disc-shaped part and said ring-shaped member, gear shifting means arranged for linear motion substantially parallel to said shaft, said gear shifting means having an inner toothing being in engagement with said first toothing arranged on said second body, and stop means limiting the motion of said gear shifting means parallel to said shaft, said stop means being arranged between said toothed rim of said first body and said second body.

5. A synchronizing gear, particularly for motor-vehicles, comprising, in combination, a shaft, a first body arranged loosely on said shaft, said first body having a toothed rim, a second body arranged on said first body in fixed axial relationship thereto near said toothedrim thereof, said second body having a conically shaped part, a disc-shaped part arranged for rotation with said shaft and extending near said conically shaped part of said second body, a first toothing arranged on said second body, a ring-shaped member having a conically shaped surface abutting against said conically shaped part of said second body so that said ring-shaped member'may be imparted a limited movement relative to said second body in a direction substantially parallel tosaid shaft, a second toothing arranged on said ring-shaped member and being arranged for alignment with said first toothing arranged on said second body, said disc-shaped part and said ring-shaped member being provided with equidistant circumferentially recesses, locking means arranged, respectively, in said circumferential recesses of said disc-shaped part and. said ring-shaped member, gear shifting means arranged for linear motion substantially parallel to said shaft, said gear shifting means having an inner toothing being in engagement with said first toothing arranged on said second body, and arrannular disc arranged at the end of said toothed rim of said first body adjacent to said second body, said annular disc forming a stop limiting the motion of said gear shifting means parallel to said shaft.

6. A synchronizing gear as claimed in claim 5,.said' annular disc having an outer perimeter projecting beyond said first toothing arranged on said second body so as to limit the motion of said gear shifting means parallelto said shaft.

References Cited in the file of this patent FOREIGN PATENTS 529,517 Great Britain Nov. 22, 1940 

